Concrete Slump Test Calculator — Concrete-Depot.com

Project Name (For Report)

Top Diameter (in) Standard is 4 in (100 mm) Must be greater than 0

Bottom Diameter (in) Standard is 8 in (200 mm) Must be greater than 0

Cone Height (in) Standard is 12 in (300 mm) Must be greater than 0

Measured Slump (in) Difference between cone height and settled concrete

Target Slump (Optional) (in)

Current Water (Optional) (lbs/yd³)

Slump Cone Volume –

Slump Classification –

Estimated Water Adjustment –

New Estimated Water Content –

Prep: Dampen the inside of the slump cone and place it on a flat, moist, non-absorbent surface. Hold it firmly in place.
Fill: Fill the cone in three equal layers by volume. Rod each layer 25 times with a tamping rod.
Strike off: After the third layer, strike off the excess concrete to make the top level with the cone.
Lift: Remove the cone by lifting it straight up in 5–7 seconds. Do not twist or rock the cone.
Measure: Invert the cone and place it next to the slumped concrete. Measure the vertical difference between the top of the cone and the highest point of the slumped concrete.

Class	Slump Range (mm)	Slump Range (in)	Typical Use
S1	10 – 40 mm	0.5 – 1.5 in	Low workability, dry mixes
S2	50 – 90 mm	2.0 – 3.5 in	Standard reinforced foundations
S3	100 – 150 mm	4.0 – 6.0 in	Standard pumped concrete, slabs
S4	160 – 210 mm	6.5 – 8.5 in	High workability, heavily reinforced
S5	≥ 220 mm	≥ 8.5 in	Flowing concrete, self-consolidating

Cone Volume (Frustum):
V = (π × h / 3) × (R² + R×r + r²)
Where h = height, R = bottom radius, r = top radius.

Water Adjustment (ACI 211.1 Estimate):
For every 1 inch (25 mm) of slump increase, water demand increases by approximately 4 lbs/yd³ (2.4 kg/m³). This is a nominal estimate; actual mix design should be verified by a licensed engineer.